Frequency analysis of sensor data is usefully used in a wide variety of situations. For example, in the case of an optical pulse wave sensor, data acquired from the pulse wave sensor, for example, a signal associated with a strength of light transmitted through or reflected from a measurement target part is subjected to a frequency analysis such as a fast Fourier transform, and a peak value of a frequency spectrum obtained as a result of the frequency analysis is determined thereby detecting a pulse rate.
In a case where data acquired from the pulse wave sensor is all transmitted to a particular output destination such as a desktop computer, a server apparatus, or the like, this causes an increase in power consumed in wireless communication. To handle the above situation, a function of frequency analysis may be provided in the sensor and a pulse rate may be transmitted instead of transmitting all sensor data thereby reducing the power consumed in the wireless communication.
In a case where a sensor module is realized by implementing the function of frequency analysis in the sensor, the sensor module may be used in a wearable device such as a band-type device, or may be used to provide one of functions of a smartphone or the like. As an example of the related art, a technique disclosed in Japanese Laid-open Patent Publication No. 2002-222177 is known.